Disk cache: Reference CL for the implementation of file format version 3.

net/disk_cache/v3/backend_work_item.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_DISK_CACHE_V3_BACKEND_WORK_ITEM_H_
+#define NET_DISK_CACHE_V3_BACKEND_WORK_ITEM_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "net/base/completion_callback.h"
+#include "net/base/io_buffer.h"
+#include "net/disk_cache/storage_block.h"
+#include "net/disk_cache/v3/backend_impl_v3.h"
+#include "net/disk_cache/v3/entry_impl_v3.h"
+
+namespace disk_cache {
+
+struct EntryRecord;
+struct EntrySet;
+struct IndexBitmap;
+struct IndexBucket;
+struct IndexHeaderV3;
+typedef StorageBlock<EntryRecord> CacheEntryBlockV3;
+typedef StorageBlock<ShortEntryRecord> CacheShortEntryBlock;
+
+struct InitResult {
+  // The index:
+  IndexBitmap* index_bitmap;
+  IndexBucket* main_table;
+  IndexBucket* extra_table;
+  scoped_ptr<IndexHeaderV3> backup_header;
+  scoped_ptr<uint32[]> backup_bitmap;
+  // Block files:
+  BlockFilesBitmaps block_bitmaps;
+  // Stats:
+  scoped_ptr<char[]> stats_data;
+};
+
+class BackendImplV3::WorkItem : public base::RefCountedThreadSafe<WorkItem> {
+ public:
+  enum WorkType {
+    WORK_INIT,
+    WORK_CLEANUP,
+    WORK_RESTART,
+    WORK_GROW_INDEX,
+    WORK_GROW_FILES,
+    WORK_WRITE_INDEX,
+    WORK_OPEN_ENTRY,
+    WORK_READ_DATA,
+    WORK_WRITE_DATA,
+    WORK_MOVE_DATA,
+    WORK_TRUNCATE,
+    WORK_DELETE,
+    WORK_CLOSE,
+    WORK_NONE
+  };
+
+  enum Flags {
+    WORK_FOR_DOOM = 1 << 0,
+    WORK_FOR_RESURRECT = 1 << 1,
+    WORK_FOR_EVICT = 1 << 2,
+    WORK_NO_COPY = 1 << 3,  // Don't copy old data on eviction.
+    WORK_FOR_UPDATE = 1 << 4,
+    WORK_FOR_ITERATION = 1 << 5,
+    WORK_FOR_DOOM_RANGE = 1 << 6,
+    WORK_COMPLETE = 1 << 7
+  };
+
+  explicit WorkItem(WorkType type);
+
+  void Start(BackendImplV3::Worker* worker);
+  void DoLoop(int result);
+  void OnDone();
+
+
+  // Getters.
+  WorkType type() const { return type_; }
+  const net::CompletionCallback& user_callback() const {
+    return user_callback_;
+  }
+  int result() const { return result_; }
+  uint32 flags() const { return flags_; }
+  scoped_ptr<InitResult> init_result() { return init_result_.Pass(); }
+  EntrySet* entries() { return &entries_; }
+  const std::string& key() const { return key_; }
+  Entry** entry_buffer() { return entry_buffer_; }
+  scoped_ptr<EntryRecord> entry_record() { return entry_record_.Pass(); }
+  scoped_ptr<ShortEntryRecord> short_entry_record() {
+    return short_entry_record_.Pass();
+  }
+  EntryImplV3* owner_entry() { return owner_entry_.get(); }
+  base::Time initial_time() const { return initial_time_; }
+  base::Time end_time() const { return end_time_; }
+  IndexIterator* iterator() { return iterator_.get(); }
+  IndexIterator* ReleaseIterator() { return iterator_.release(); }
+  void** iter_buffer() const { return iter_buffer_; }
+
+  // Setters.
+  void set_user_callback(const net::CompletionCallback& callback) {
+    user_callback_ = callback;
+  }
+  void set_closure(const base::Callback<void(WorkItem*)>& closure) {
+    closure_ = closure;
+  }
+  void set_flags(uint32 flags) { flags_ = flags; }
+  void set_entries(EntrySet entries) { entries_ = entries; }
+  void set_key(const std::string& key) { key_ = key; }
+  void set_entry_buffer(Entry** entry_buffer) { entry_buffer_ = entry_buffer; }
+  void set_buffer(net::IOBuffer* buffer) { buffer_ = buffer; }
+  void set_buffer_len(int buffer_len) { buffer_len_ = buffer_len; }
+  void set_address(Addr address) { address_ = address; }
+  void set_address2(Addr address) { address2_ = address; }
+  void set_offset(int offset) { offset_ = offset; }
+  void set_owner_entry(EntryImplV3* entry) { owner_entry_ = entry; }
+  void set_initial_time(base::Time time) { initial_time_ = time; }
+  void set_end_time(base::Time time) { end_time_ = time; }
+  void set_iterator(scoped_ptr<IndexIterator> iterator) {
+    iterator_ = iterator.Pass();
+  }
+  void set_iter_buffer(void** iter) { iter_buffer_ = iter; }
+  
+ private:
+  friend class base::RefCountedThreadSafe<WorkItem>;
+
+  enum State {
+    STATE_NONE,
+    STATE_OPEN_ENTRY,
+    STATE_OPEN_ENTRY_COMPLETE,
+    STATE_READ_KEY,
+    STATE_READ_KEY_COMPLETE,
+    STATE_READ_DATA,
+    STATE_READ_DATA_COMPLETE,
+    STATE_WRITE_DATA,
+    STATE_WRITE_DATA_COMPLETE,
+    STATE_MOVE_DATA,
+    STATE_TRUNCATE_DATA,
+    STATE_COPY_ENTRY,
+    STATE_COPY_ENTRY_COMPLETE
+  };
+
+  ~WorkItem();
+
+  void CompleteItem(int result);
+  int DoOpenEntry();
+  int DoOpenEntryComplete(int result);
+  int DoReadKey();
+  int DoReadKeyComplete();
+  int DoReadData();
+  int DoReadDataComplete(int result);
+  int DoWriteData();
+  int DoWriteDataComplete(int result);
+  int DoMoveData();
+  int DoTruncateData();
+  int DoCopyEntry();
+  int DoCopyEntryComplete(int result);
+
+  int LoadEntryBlock(Addr address);
+  int LoadShortEntryBlock(Addr address);
+
+  WorkType type_;
+  net::CompletionCallback user_callback_;
+  base::Callback<void(WorkItem*)> closure_;
+  int result_;
+  scoped_refptr<BackendImplV3::Worker> worker_;
+  State next_state_;
+
+  // Init.
+  uint32 flags_;
+  scoped_ptr<InitResult> init_result_;
+
+  // Open.
+  EntrySet entries_;
+  std::string key_;
+  Entry** entry_buffer_;
+  scoped_ptr<EntryRecord> entry_record_;
+  scoped_ptr<ShortEntryRecord> short_entry_record_;
+  scoped_ptr<CacheEntryBlockV3> entry_block_;
+  scoped_ptr<CacheShortEntryBlock> short_entry_block_;
+
+  // Read/Write.
+  scoped_refptr<net::IOBuffer> buffer_;
+  int buffer_len_;
+  Addr address_;
+  Addr address2_;
+  int offset_;
+  scoped_refptr<EntryImplV3> owner_entry_;
+
+  // Iteration.
+  base::Time initial_time_;
+  base::Time end_time_;
+  scoped_ptr<IndexIterator> iterator_;
+  void** iter_buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(WorkItem);
+};
+
+}  // namespace disk_cache
+
+#endif  // NET_DISK_CACHE_V3_BACKEND_WORK_ITEM_H_